SPRINGVILLE — The mystery surrounding the weekend deaths of five members of a family remained unsolved Monday, and police say it may take a month or longer before any answers are known.

The bodies of Benjamin Strack, 37, his wife, Kristi Strack, 36, and three of their children, Benson, 14, Emery, 12, and Zion, 11, were discovered by the Stracks' oldest son and his grandmother about 8 p.m. Saturday.

All of the victims were found inside the parents' bedroom at 954 E. 900 South.

As of Monday, investigators remained stumped about how the family died. The only thing that seemed to be clear is that there isn't a killer on the loose.

"There was no blunt force trauma, no stab wounds, no gunshot wounds," said Springville Police Lt. Dave Caron. "Nobody went in the house and shot these people or stabbed these people."

But exactly how the Stracks died remained the biggest unknown Monday.

"What's left is something chemical, like carbon monoxide or a poison," Caron said.

However, there were no obvious signs of either of those elements when police entered the bedroom Saturday night.

"There's nothing that screamed anything," he said. "There's nothing, no note, no barbecue or gas heater, no container with a skull and cross bones on it."

The medical examiner is now waiting for toxicology tests to be completed, which could take at least a month.

Caron said investigators determined that the last confirmed time someone talked with the family was about 7 a.m. Saturday. The bodies were discovered in the upstairs bedroom about 8 p.m.

Police arrived at the scene a short time later. At least one door, possibly two going into the home were open as officers arrived. Strong winds from an approaching storm were also starting to build at that time.

Fire crews arrived about 10 minutes after police. When they measured for carbon monoxide levels and other gases in the duplex, they found the structure was safe to enter, Caron said. Whether that meant there weren't any dangerous levels of carbon monoxide in the duplex to begin with, or if enough of any gas had been blown out of the house by then was unknown Monday.

"I have no reason to think that it is (carbon monoxide), but I don't have any reason to think it isn't," Caron said.

A kitten found locked in a separate room was found alive.

A large screen TV as well as bottled water and soda pop were found inside the room where the bodies were located. One scenario being looked at is whether the family had gathered in the room to watch a movie.

Caron said samples of the drinks were sent away to the Utah State Crime Lab for testing. In addition, notebooks and possibly cellphones were all collected as detectives searched for any possible clue as to what might have happened.

"Now we wait," he said of the sometimes long process it takes for tests to be completed.

There was a fan in the window that was not running when officers first arrived, but later it turned on and blew outside air into the house, Caron said. He did not know what triggered it or if it was connected to a thermostat. He also did not know Monday if the fan was just a cooler or also could be used as a heater.

Meanwhile, as trust funds and funeral plans were being made for the Strack family, a friend designated by relatives to act as a spokesman, pleaded for privacy.

"They are still very much grieving," said Jim Phillips.

The Stracks have been described by neighbors as shy and people who mostly kept to themselves. The three children were home-schooled.

On a Facebook page set up in memorial of the family, many local family members left comments to console each other, mourn and share memories.